/Engine/Plugins/Editor/ObjectMixer/ObjectMixer/Source/ObjectMixer/Public/Views/List/SObjectMixerEditorList.h
[TSet](API\Runtime\Core\Containers\TSet)< [TWeakPtr](API\Runtime\Core\Templates\TWeakPtr)< [ISceneOutlinerTreeItem](API\Editor\SceneOutliner\ISceneOutlinerTreeItem) > > GetWeakTreeRootItems() const